JP4349336B2 - Light irradiation device - Google Patents

Description

  The present invention relates to a light irradiation apparatus using a light emitting diode as a light source, and more particularly to a light irradiation apparatus suitable for use in an ultraviolet curing apparatus that irradiates ultraviolet rays to cure a photocurable resin.

  Conventionally, in an ultraviolet curing device that irradiates and cures light such as ultraviolet rays to a photocurable resin, a light irradiation device using a discharge lamp or a laser oscillator as a light source has been used, but recently, a light emitting diode is used as a light source. Light irradiation devices are becoming widespread (for example, Patent Document 1).

For example, a light irradiation apparatus as shown in FIG. 3 is provided. This light irradiation device includes a cylindrical casing 100 having an open front surface, a light emitting diode 101 housed in the casing 100 with the front direction as the optical axis direction, and a state positioned on the optical axis of the light emitting diode 101 A hemispherical lens 102 disposed in the housing 100, and a plano-convex lens 103 disposed in the housing 100 in a state of being positioned on the optical axis of the light emitting diode 101 and in front of the hemispherical lens 102, A drive current can be supplied to the light emitting diode 101 by a cable (not shown).
Japanese Patent Laying-Open No. 2003-291153 (FIG. 1)

  By the way, in the conventional light irradiation apparatus as shown in FIG. 3, the hemispherical lens 102 and the plano-convex lens 103 for condensing the light of the light emitting diode 101 are formed using a lens fixing component 104. It is fixed at a predetermined position of 100. In particular, as the lens fixing component 104, an annular (cylindrical) lens holding screw having a thread groove formed on its outer peripheral surface has been conventionally used. Such a lens holding screw is used as a housing of a light irradiation device. By screwing into a thread groove formed on the inner peripheral surface of the body, the peripheral edge of the lens can be fixed to the casing of the light irradiation device with a lens pressing screw over the entire circumference.

  However, when such an annular lens holding screw is used, the lens holding screw covers the entire periphery of the lens, so that the light from the light-emitting diode is blocked at the periphery of the lens. As a result, the effective diameter of the lens is reduced, and the light coupling efficiency is reduced. In particular, if the effective diameter of the lens that first transmits light from the light-emitting diode is small, a large amount of light with high energy density is blocked, resulting in a significant reduction in light coupling efficiency. It was.

  The present invention has been made in view of the above points, and an object thereof is to provide a light irradiation apparatus capable of improving the light coupling efficiency.

In order to solve the above-described problem, in the invention of the light irradiation device according to claim 1, a cylindrical housing having an open front surface, a light emitting diode housed in the housing with the front direction as the optical axis direction, A first lens disposed in the housing in a state positioned on the optical axis of the light emitting diode; and a first lens disposed in the housing in a state positioned on the optical axis of the light emitting diode and in front of the first lens. A holding portion to which the first lens is bonded and fixed using an adhesive, and a front surface portion of the holding portion is formed in a concave shape. , the front portion of the holding portion, the positioning recess rear end engaging and performs positioning of the first lens of the first lens is provided, wherein the bottom of the positioning recess of the light-emitting diode An opening for allowing light to enter the first lens is provided, and the contact Agent is characterized by being applied to over the front of the the opening edge of the positioning recess of the holding portion first lens.

According to a second aspect of the present invention, in the first aspect of the invention, a positioning convex portion having a predetermined thickness and fitted with the positioning concave portion is provided on the rear end side of the first lens. It is characterized by that.

According to a third aspect of the present invention, the light emitting diode is fixed to a rear surface portion of the holding portion.

In the invention of the light irradiation apparatus according to claim 4, in the invention of any one of claims 1 to 3, wherein the housing includes a body portion having the holding portion to which the first lens is bonded and fixed, the is composed of a lens holder in which the second lens is fixed, the lens holder is characterized in that is detachably attached to the front side of the main body portion.

In the invention of the light irradiation apparatus according to claim 5, characterized in that in the invention of claim 4, wherein the lens holder is provided with a contacting flange at the edge of the front side of the second lens, a circle having a screw groove on an outer circumferential surface the screw groove corresponding to the annular lens presser screw provided on the inner peripheral surface of the rear than the flange portion, the second lens is fixed to the lens holder while being sandwiched between the back and forth and the lens cap screw and the flange portion It is characterized by being.

  In the present invention, since the housing is provided with a holding portion to which the first lens is bonded and fixed by the adhesive, the portion covering the lens can be reduced as compared with the case where the first lens is fixed by using an annular screw. As a result, the effective diameter of the lens can be made larger than that of the conventional lens, so that the light coupling efficiency can be improved.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 and 2. In the following embodiments, the right side of FIG. 1A is the front side of the light irradiation device, and the left side of FIG. 1A is the rear side of the light irradiation device.

  The light irradiation device of the present embodiment includes a cylindrical housing 1 having an open front surface, a light emitting diode 2 housed in the housing 1 with the front-rear direction as the optical axis X direction, and the optical axis X of the light emitting diode 2. The first lens 3 disposed in the housing 1 in a state of being positioned above, and disposed in the housing 1 in a state of being positioned on the optical axis X of the light emitting diode 2 and in front of the first lens 3. A second lens 4, a thermistor temperature measuring element 7 that is arranged in the vicinity of the light emitting diode 2 to measure the temperature of the light emitting diode 2, and a cable 8 for connecting the light emitting diode 2 and the thermistor temperature measuring element 7 to an external device; The first lens 3 is bonded and fixed to the holding portion 5 protruding from the inner surface of the housing 1 using an adhesive B, and the second lens 4 uses a lens holding screw 6. The housing 1 is fixed.

  First, the light emitting diode 2, the first lens 3, and the second lens 4 housed in the housing 1 will be described. The light-emitting diode 2 is, for example, a surface-mount type ultraviolet light-emitting diode having a peak wavelength in the ultraviolet region, with the emission surface facing forward and the mounting surface where the anode terminal and the cathode terminal are exposed facing backward and the optical axis X being It is housed in the housing 1 in a state of being aligned with the central axis of the housing 1. The first lens 3 is a plano-convex lens used to capture and propagate the light of the light emitting diode 2 so that the light of the light emitting diode 2 is irradiated on the entire surface of the second lens 4. A substantially hemispherical lens portion 3a having a small outer diameter, and a cylindrical edge portion 3b having the same outer diameter as that of the lens portion 3a and protruding integrally with the rear portion of the lens portion 3a. Has been. The second lens 4 is for setting the irradiation range and focal length of the light irradiating device. In this embodiment, the inner diameter of the middle part of the lens holder 14 to be described later is larger than the outer diameter of the first lens 3. A biconvex lens having the same outer diameter as that of the lens.

  Next, the housing 1 will be described. As shown in FIG. 1A, the housing 1 has a cylindrical shape with an open front surface, an LED holder 11 provided with a holding portion 5 to which the light emitting diode 2 and the first lens 3 are fixed, and a cable. 8 is attached to and detached from the front side of the main body 10 (that is, the front side of the LED holder 11). The main body 10 is composed of a cable holder 12 for holding 8 and a cylindrical body 13 for connecting the LED holder 11 and the cable holder 12. It is comprised with the lens holder 14 attached freely.

  The LED holder 11 is formed in a cylindrical shape using, for example, an aluminum alloy that has been subjected to anodizing treatment and sealing treatment (so-called anodized treatment). The front end portion of the LED holder 11 has an outer diameter smaller than that of the rear end side, and a male screw portion 11a for attaching the lens holder 14 is formed on the outer peripheral surface thereof. In addition, an internal thread portion 11 b for attaching the cylindrical body 13 is formed on the inner peripheral surface on the rear end side of the LED holder 11.

  On the other hand, on the inner surface on the front end side of the LED holder 11 (that is, the inner surface of the housing 1), a holding portion 5 to which the first lens 3 is bonded and fixed using the adhesive B is integrally projected. The holding portion 5 is formed in a substantially disc shape so as to close the front opening of the LED holder 11, and a positioning recess 5 a having substantially the same shape as the edge portion 3 b of the first lens 3 is recessed in the front portion. It is installed. In addition, an opening 5c penetrating the holding portion 5 in the front-rear direction is provided at the bottom 5b of the positioning recess 5a, so that light from the light emitting diode 2 can be incident on the first lens 3 through the opening 5c. I have to. Incidentally, the central axis of the positioning recess 5a and the opening 5c of the holding part 5 is set to coincide with the optical axis X of the light emitting diode 2, so that when the first lens 3 is fixed to the holding part 5, Is configured so that the central axis of the first lens 3 and the optical axis X coincide with each other automatically. In addition, the holding part 5 does not need to be formed integrally with the LED holder 11 and may be formed from a separate member and bonded using an adhesive or the like.

  The cable holder 12 is formed in a cylindrical shape having substantially the same outer diameter as that of the LED holder 11 by using an aluminum alloy that has been subjected to anodizing treatment and sealing treatment in the same manner as the LED holder 11, and inside the outer diameter of the cable 8. A holding hole 12a that is slightly larger than that is penetrated. The cable holder 12 is provided with a screw hole 12b that communicates the holding hole 12a with the outside in the radial direction. The screw hole 12b has a screw (for fixing the cable 8 to the cable holder 12). (Not shown) are screwed from the outside. In addition, on the inner peripheral surface on the front end side of the cable holder 12, a female screw portion 12c for attaching the cylindrical body 13 is formed. Here, the cable 8 will be briefly described. The cable 8 is a bundle of four electric wires 8a to 8d, as shown in FIG. It is used to supply and obtain the output from the thermistor temperature measuring element 7.

  The cylindrical body 13 is formed in a cylindrical shape having substantially the same outer diameter as the LED holder 11 and the cable holder 12 by using an aluminum alloy that has been subjected to anodizing treatment and sealing treatment in the same manner as the LED holder 11 and the cable holder 12. Yes. A cylindrical first projecting portion 13a having an outer diameter approximately the same as the inner diameter of the rear end portion of the LED holder 11 is integrally provided at the front end portion of the cylindrical body 13 so as to project. A male screw portion 13 b corresponding to the female screw portion 11 b of the LED holder 11 is provided on the outer peripheral surface of the portion 13 a. Further, a cylindrical second protruding portion 13c having an outer diameter approximately the same as the inner diameter of the front end portion of the cable holder 12 is integrally projected at the rear end portion of the cylindrical body 13, A male screw portion 13d corresponding to the female screw portion 12c of the cable holder 12 is provided on the outer peripheral surface of the two protruding portions 13c.

  The lens holder 14 is formed in a cylindrical shape having substantially the same outer diameter as that of the LED holder 11 using an aluminum alloy that has been subjected to anodizing treatment and sealing treatment in the same manner as the LED holder 11. An annular flange portion 14a projecting inward is integrally formed on the opening edge portion on the front end side of the lens holder 14, and the opening portion 14b of the lens holder 14 surrounded by the flange portion 14a is irradiated with light. Used as an irradiation port of the apparatus. Further, the rear end portion of the lens holder 14 has an inner diameter that is substantially the same as the outer diameter of the front end portion of the LED holder 11, and the inner peripheral surface thereof has a male screw portion 11 a of the LED holder 11. A corresponding female thread portion 14c is formed. Furthermore, a thread groove 14d for the lens holding screw 6 is formed on the inner peripheral surface of the portion of the lens holder 14 (hereinafter referred to as the middle abdomen) behind the flange portion 14a and ahead of the female screw portion 14c.

  Here, the lens holding screw 6 will be described. The lens holding screw 6 is a circle having an outer diameter similar to the inner diameter of the middle part of the lens holder 14 using an aluminum alloy that has been anodized and sealed as in the LED holder 11 and the like. It is formed in an annular shape, and a thread groove 6 a corresponding to the thread groove 14 d of the lens holder 14 is provided on the outer peripheral surface. A rectangular notch 6b is formed at the rear end of the lens holding screw 6 so that the lens holding screw 6 can be easily screwed into the lens holder 14.

  As described above, the light irradiation apparatus according to the present embodiment includes the main body portion 10 including the LED holder 11, the cable holder 12, and the cylindrical body 13, and the lens holder 14 that is detachably attached to the main body portion 10. A light-emitting diode 2, a first lens 3, a second lens 4, a lens holding screw 6, a thermistor temperature measuring element 7, and a cable 8. Next, the assembly method will be described.

  First, the light emitting diode 2 is attached to the rear surface portion of the holding portion 5 of the LED holder 11 by bonding or the like. At this time, the irradiation surface of the light emitting diode 2 is made to face forward from the opening portion 5c of the holding portion 5. . Next, one end of each lead wire 9 is soldered to a cathode terminal and an anode terminal (not shown) of the mounting surface of the light emitting diode 2, and a copper pipe 70 is fixed to the mounting surface of the light emitting diode 2, and the thermistor therein. The temperature measuring element 7 is accommodated. Thereafter, the other ends of the lead wires 9 connected to the light emitting diode 2 are caulked and fixed to the electric wires 8a and 8b of the cable 8, respectively, and the leads 7a and 7b of the thermistor temperature measuring element 7 are connected to the electric wires 8c and 8d of the cable 8. The cable 8 is electrically connected to the light emitting diode 2 and the thermistor temperature measuring element 7. Further, the connecting portion between the leads 7 a and 7 b of the thermistor temperature measuring element 7 and the wires 8 c and 8 d of the cable 8 is protected by covering with an insulating tube T.

  Next, the male screw portion 13 b of the cylindrical body 13 is screwed into the female screw portion 11 b of the LED holder 11, and the cylindrical body 13 is attached to the LED holder 11. In this state, the tube 13 and the LED holder 11 are filled with a thermosetting potting (sealing) material P having a high thermal conductivity from the rear end side of the tube 13, and then the potting material P is heated and cured. Let As such a potting material P, for example, a thermosetting silicone rubber having a thermal conductivity of about 2.5 [W / m · K] is suitable. Further, when filling the potting material P, it is desirable to fill while removing the air in the tube body 13 and the LED holder 11 in order to prevent generation of bubbles. Then, the female screw portion 12c of the cable holder 12 is screwed into the male screw portion 13d of the cylindrical body 13, the cable holder 12 is attached to the cylindrical body 13, and the cable 8 inserted through the holding hole 12a of the cable holder 12 is screwed into the screw hole. The main body 10 is configured by tightening with a screw (not shown) screwed into 12b. The potting material P may be filled in the cable holder 12 as well.

  The first lens 3 is attached to the main body 10 thus configured as follows. That is, the edge portion 3b on the rear end side of the first lens 3 is fitted into the positioning recess 5c of the holding portion 5, and in this state, as shown in FIG. The adhesive B is adhesively fixed to the holding portion 5 at four locations so as to be divided into four equal parts. Here, as such an adhesive B, for example, a one-component moisture-curing elastic adhesive or the like is used, and various other adhesives can be used. Further, the bonding location by the adhesive B is not limited to the above four locations, and the first lens 3 may be bonded to the holding portion 5 at a suitable location, but in this case, the adhesive is excessive. It is preferable to apply an amount appropriate for fixing the first lens 3 without applying it so as to increase the effective diameter of the first lens 3.

  On the other hand, the second lens 4 is attached to the lens holder 14 as follows. That is, the second lens 4 is inserted into the lens holder 14 from the rear end side, the front surface portion of the second lens 4 is brought into contact with the rear surface side of the flange portion 14a of the lens holder 14, and the second lens 4 is irradiated to the irradiation port 14b. The lens holding screw 6 is attached to the lens holder 14 by screwing the screw groove 6a of the lens holding screw 6 into the screw groove 14d of the lens holder 14, and then as shown in FIG. In addition, the lens holding screw 6 is brought into contact with the rear surface portion of the second lens 4, whereby the second lens 4 is sandwiched from the front and rear by the flange portion 14 a and the lens holding screw 6, whereby the second lens 4 is held by the lens holder 14. It is fixed to.

  Then, by screwing the male screw portion 11a of the LED holder 11 into the female screw portion 14c of the lens holder 14, the lens holder 14 is detachably attached to the main body portion 10, thereby completing the light irradiation device of the present embodiment. It will be.

  Here, the light irradiation device of the present embodiment, the light irradiation device of the conventional example shown in FIG. 3, and the light irradiation device using a spherical lens instead of the hemispherical lens 102 in the conventional example shown in FIG. When the intensity distribution was measured, the results shown in FIG. 2 were obtained. In the figure, a is the light irradiation device of this embodiment, b is the conventional light irradiation device shown in FIG. 3, and c is a spherical lens instead of the hemispherical lens 102 in the conventional example shown in FIG. Light irradiation device. In FIG. 2, the light intensity is shown as a relative value with a value (center intensity) when the irradiation range is 0 mm in c as a reference value, and the measurement of the light intensity was performed at an irradiation distance of 10 mm. . Other conditions (type of light emitting diode and magnitude of drive current) are fixed conditions.

  As is apparent from the result of this measurement with reference to FIG. 2, the light irradiation device of this embodiment has a center intensity approximately 1.8 times that of the conventional example, and the light intensity is greatly improved. I understand that.

  According to the light irradiation apparatus of the present embodiment described above, the holding part 5 to which the first lens 3 is bonded and fixed by the adhesive B is provided in the housing 1, so that an annular screw is used as in the prior art. Compared to the case of fixing, it is possible to reduce the portion of the lens that covers the lens, and as a result, the effective diameter of the lens, that is, the effective portion of the lens (the portion that transmits light) can be increased. Efficiency can be improved. In particular, since the effective diameter of the first lens on which light from the light emitting diode 2 is first incident is increased, it is possible to prevent a large amount of light with high energy density from being blocked. The light coupling efficiency can be improved.

  In addition, since the positioning recess 5c is provided in the holding portion 5 and the first lens 3 is fitted into the recess 5c, the first lens 3 can be easily and accurately arranged at a predetermined position. . In addition, since the edge portion 3b which has a predetermined thickness and serves as a positioning convex portion to be fitted to the positioning concave portion 5c is provided at the rear end portion of the first lens 3, the holding portion 5 and the first lens 3 are provided. And the first lens 3 can be easily positioned. However, the first lens 3 of the present embodiment is not limited to the one provided with the edge portion 3b, and may be a hemispherical lens without the edge portion 3b.

  In addition, since the light emitting diode 2 and the first lens 3 are arranged close to each other by fixing the light emitting diode 2 to the rear surface portion of the holding portion 5, the light of the light emitting diode 2 is efficiently incident on the first lens 3. In addition, since it is not necessary to newly provide a portion for fixing the light emitting diode 2, the number of parts can be reduced and assembly can be easily performed. At this time, if the thickness of the holding portion 5 is reduced, the light emitting diode 2 and the first lens 3 can be brought closer to each other, and the light from the light emitting diode 2 can be incident on the first lens 3 more efficiently.

  Further, the housing 1 is constituted by a lens holder 14 to which the second lens 4 is fixed, and a main body portion 10 provided with the first lens 3, the light emitting diode 2, the holding portion 5 and the like. 10 can be detachably attached to the front side of the lens 10, so that only the lens holder 14 can be easily separated from the housing 1, and the lens holder 14 can be easily replaced. Therefore, for example, if a lens holder to which a second lens having a different curvature radius and thickness is attached is prepared, the focal length of the light irradiation device can be easily adjusted by replacing the lens holder. Further, since the second lens 4 is fixed to the lens holder 14 with the flange 14a of the lens holder 14 and the lens holding screw 6 sandwiched between the front and rear, the second lens 4 can be removed by simply removing the lens holding screw 6. The time required for mounting the second lens 4 to the lens holder 14 (mounting tact) can be shortened, and even if the second lens 4 is damaged, the second lens 4 can be easily replaced with a new one. Can be replaced.

  On the other hand, in the light irradiation apparatus of this embodiment, since the potting material P is filled in the housing 1 and then heated and cured, the light emitting diode 2 and the housing 1 are thermally passed through the potting material P. The heat generated by the light emitting diodes 2 is conducted to the housing 1 through the potting material P to promote heat dissipation, thereby suppressing the temperature rise of the light emitting diodes 2 and preventing the light emission efficiency from being lowered. it can. Further, since the thermistor temperature measuring element 7 for measuring the temperature of the light emitting diode 2 is provided, the luminance accompanying the temperature rise of the light emitting diode 2 based on the temperature of the light emitting diode 2 detected by the thermistor temperature measuring element 7. It is possible to correct the decrease in the level.

  By the way, in this embodiment, a plano-convex lens is used as the first lens 3 and a biconvex lens is used as the second lens 4. However, the shape of each lens 3, 4 is not limited to the above, and the situation What is necessary is just to select a suitable thing according to. Further, the number of lenses constituting the optical system is not limited to two, and third and fourth lenses may be provided between the first lens 3 and the second lens 4, or other optical components. May be provided.

  Further, the light emitting diode 2 is not limited to the ultraviolet region, and a blue light emitting diode or other light emitting diodes of various light colors may be used, and the number of the light emitting diodes 2 is limited to one. However, it goes without saying that a plurality of light emitting diodes may be provided. In addition, the external shape of the light irradiation device is not limited to that of the embodiment, and may be designed in a suitable shape according to the situation.

(A) is a schematic sectional drawing of one Embodiment of the light irradiation apparatus of this invention, (b) is sectional drawing in the AA line of the figure (a). It is a graph which shows distribution of light intensity. It is a schematic sectional drawing of the principal part of the conventional light irradiation apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Case 2 Light emitting diode 3 1st lens 4 2nd lens 5 Holding part 6 Lens holding screw 7 Thermistor temperature measuring element 8 Cable B Adhesive X Optical axis

Claims (5)

A cylindrical housing having an open front surface, a light emitting diode housed in the housing with the front direction as the optical axis direction, and a first housing disposed in the housing in a state of being positioned on the optical axis of the light emitting diode One lens, and a second lens disposed in the casing in a state of being positioned on the optical axis of the light emitting diode and in front of the first lens,
A holding portion to which the first lens is bonded and fixed using an adhesive protrudes from the inner surface of the housing,
The front part of the holding part is formed in a concave shape,
A positioning recess for positioning the first lens by being fitted to the rear end side of the first lens is provided on the front surface of the holding portion,
An opening for allowing light from the light emitting diode to enter the first lens is provided at the bottom of the positioning recess,
The light irradiation apparatus, wherein the adhesive is applied so as to extend over an opening edge portion of a positioning recess of the holding portion and the front surface of the first lens.   2. The light irradiation apparatus according to claim 1, wherein a positioning convex portion that has a predetermined thickness and is fitted to the positioning concave portion is provided on a rear end side of the first lens.   The light emitting device according to claim 1, wherein the light emitting diode is fixed to a rear surface portion of the holding portion. The housing includes a main body having the holding unit to which the first lens is bonded and fixed, and a lens holder to which the second lens is fixed.
The light irradiation apparatus according to claim 1, wherein the lens holder is detachably attached to the front side of the main body. The lens holder includes a flange portion that comes into contact with an edge on the front surface side of the second lens, and a thread groove corresponding to an annular lens holding screw having a thread groove on the outer peripheral surface is provided on the inner side behind the flange portion. In preparation for the circumference,
The light irradiation apparatus according to claim 4, wherein the second lens is fixed to the lens holder in a state where the front and rear are sandwiched between the flange portion and the lens holding screw.

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